Apparatus for treating one surface of a strip



Dec. 16, 1958 L. v. SORG ETAL 2,

APPARATUS FOR TREATING ONE SURFACE OF A STRIP Filed Dec. 29, 1955 2Sheets-Sheet 1 e07 Wa kw 66:21-31 wax f; 3

- zzma 9 6? Dec. 16, 1958 v. SORG HAL 2,864,333

APPARATUS FOR TREATING ONE SURFACE OF A STRIP Filed Dec. 29, 1955 2Sheets-Sheet 2 @MZZ 07 dw/v/eegg United States Patent APPARATUS FORTREATING ONE SURFACE OF A STRIP Leonard V. Sorg, Kansas City, and ElmerBradley Oflutt,

Webster Groves, Mo., assignors to Standard Oil Company, Chicago, 111., acorporation of Indiana Application December 29, 1955, Serial No.;556,238

Claims. (Cl. 118-123) This invention relates to the continuous treatmentof strip material and, in particular, comprises improved apparatus forsensitizing one coated surface of tape or other strip material.

The manufacture of our sensitive film includes the steps of applying aliquid sensitive gelatin coating on a film support such as a continuoustransparent and fluidimpervious tape. Subsequently, the coated tape issensitized by impregnating the gelatin with a reactive solution. Inconnection with a hydrogen sulfide analyzerrecorder described in ourco-pending patent application Serial No. 375,032, now U. S. Patent No.2,800,397, We employ a sensitive-to-hydrogen-sulfide tape whichcomprises an acetate film base having a gelatin coating. Thiscorresponds to motion picture film from which the photo-sensitive silverhas been removed. By impregnation, we place a certain amount of leadacetate and sodium acetate into the gelatin coating.

An important object of the invention is to provide an improved apparatusfor continuously feeding tape or other strip material over a treatingsolution to effect a controlled impregnation of a gelatin coatingthereon. A .further object of the invention is to provide an apparatusfor the rapid, accurate and uniform treatment of the gelatin coatingWithout injury or mutilation of the base strip material. A more specificobject of the invention is to provide an apparatus Which prevents thesensitized or gelatin side of the tape from coming in contact with theparts of the apparatus along which it moves to permit the use ofrelatively small amounts of treating solution, to provide means formaintaining the surface of the solution at a constant level, and tomaintain the solution at the desired temperature. K

Another object of the invention is to provide a system utilizing asensitizing station and a drying chamber with means for feeding thesupporting tape through the station and chamber in series so that thetape will be maintained in such a position that the sensitized gelatincoating is dried without contacting any portion of the apparatus. Stillanother object is to provide a system which controls the temperature andcirculates air in the drying chamber whereby there is a progressivedrying of the coating to produce a non-tacky sensitized strip. These andother objects of our invention will become apparent as the descriptionthereof proceeds.

Briefly, we attain the objects of our invention by providing means forsuccessively impregnating and drying at gelatin coating on afluid-impermeable tape or base material which includes atemperature-controlled impregnating station which is provided with meansfor accurately maintaining the level of the impregnating solution suchthat it will contact the gelatin-coated surface of the moving tapewithout submerging the uncoated surface of the tape during theimpregnating step. The drying chamber means includes a thermostaticheating unit paralleling a substantial span of the treated tape. Furtherdetails of construction and advantages of our apparatus will bedescribed in conjunction with the accompanying drawings ice illustratinga preferred embodiment of the invention and wherein:

Figure l is an elevation, partly in section, showing one form ofapparatus for impregnating a gelatin coating on a continuous support andfor drying the impregnated coating;

Figure 2 is a side elevation, partly in section, of the apparatus shownin Figure l; s

Figure 2a is an enlarged fragmentary section of the trough taken alongthe line 2a-2a in Figure 1;

Figure 3 is a detail taken alOng the lines '33 in Figure 1;

Figure 4 is a detail taken along the lines 44 in Figure 1;

Figure 5 is a detail taken along the lines 5-5 in Figure 1;

Figure 6 is a detail taken Figure 3; and

Figure 7 is a detail taken Figure 2.

Similar reference numbers refer to corresponding parts in the severalviews of the drawings.

Referring to the drawings, the framework 10, comprising angle irons,supports 0.25 inch aluminum panel 11 upon which all of the components ofour apparatus are mounted. Four bolts or feet 12 extending through thelateral surfaces of the angle irons 10 permit adjusting the apparatus toa level position.

A compartment 13 comprised of walls 131i and hinged cover 14 comprisesthe drying chamber.

A motor 15, controlled by switch 16 and fused by 17, provides the drivefor moving the film or tape through the instrument. Gears 18 and 19driven by motor 15 drive sprocket 20 and take-up reel 21 through afriction clutch 22 driven through belt 27. An idler 23 presses the filminto engagement with sprocket 20 thereby preventing tape slippage.Tension is given to the idler 23 through pivoted arm 24 which is undertension from spring 25 attached to lever 26.

Electric heater 30 furnishes heat to control the temperature of thecabinet 13 to a constant value and motor 28 drives the squirrel cageblower 29 which circulates air through the drying compartment 13 aboutbafile 13b.

The heater 30 is shown in Figure l, but for simplicity has been omittedfrom Figure 2. Radiating fins 31 and 32 are attached to heater 30 to aidin conduction of the heat. The temperature Within the drying chamber 13is maintained constant by thermal regulator 33 and the temperature isindicated by thermometer 34.

The treating, or impregnating station 35 includes the trough 36 Withinconstant temperature bath 37. The trough 36 is provided with parallelknife edges 38 which act like a ruling pen (see Figure 2a) permitting a0.375 inch trace of chemicals to be impregnated in the gelatin coating38a on the tape 39. Excess liquid is removed from the gelatin surface bytransverse scraper 40'.

The constant temperature bath 37 comprises an alumi num block and thetemperature is maintained constant by strip heaters 41 and 42 which areControlled by thermal regulator 43, electrical power being brought tothe heating elements by lead 44. Pilot light 45 indicates when thecurrent is on. Power is furnished to motor 28 and heaters 30, 41 and 42through switch 46, the circuit being fused through 47.

Film or tape 39 from the supply reel 48 passes over rollers 49 and 50which maintain tension on sprocket 5 1. The supply reel 48 is maintainedagainst a felt brake 52 shown in Figures 3 and 6 and the brake 52 isactuated through lever 53 to which is attached bearing 54. Attached toshaft 55 which rides in bearing 54 is drum 56 which is held againstbrake pad 52 by spring 57 which along the lines '6-6 in along the lines7-7 in 3 is anchored by pin 58. The film supply reel 48 is held ontoshaft 55 by clamp 59;

Referring to Figure 5, the lever arm 53 is supported by the panel 11.Shaft 55a is held in socket 60 which is fastened to panel 11. A bearingsurface for shaft 55a is provided by collar 61, the whole assembly beingheld onto the shaft 55a by pin 62.

Sprocket 51 furnishes additional braking action against the tape 39 frompulley 63, Figures 2 and 7, on which rides a small section of roundleather belting 64 with tension applied by spring 65 which is anchoredby pin 66. All of these wheel-like mechanisms are supported to the panel11 by individual bearing members as shown in Figure 2.

Guide rollers 66 and 67 carry the tape 39 parallel to the exposed uppersurface of the impregnation trough 36 and allow the trough 36 to bevertically adjusted so that the gelatin-coated surface of the tape 39moves over the liquid surface in the trough 36.

The impregnating solution is retained in leveling bottle 69 providedwith a tube connection 70 which permits the solution to flow through theplastic tubing 71 into trough 36. The liquid level in trough 36 israised or lowered by positioning bottle 69 along the threaded rod 72 bycollar 73, which supports bottle clamp 74, the selected position beingsecured by nut 75.

The coating station 35, including the trough 36 and the constanttemperature bath 37, is adjusted by plate 76 which is fastened toplatform 77 by knurled nuts 78 and 79. Loosening the knurled nuts 78 and79 permits plate 76 to be positioned with respect to panel 11 throughslots therein.

Lateral movement of station 35, parallel to panel 11, is controlled bythe studs and knurled nuts 80 and 81 which are fastened to the troughassembly or station 35 through slots in plate 76.

The entire trough assembly 35, plate 76 and platform 77 rest on steelball 82 which in turn operates in socket 83 in platform 77 and lowersocket 84 in sub-platform 85. Stud bolts 86 and knurled nuts 87 securethe plat form 77 and the sub-platform 85 together to clamp the steelball 82 therebetween. Adjustments can be made so as to level the troughassembly 35 and to dispose the trough 36 with respect to the panel 11and the path of travel of the tape 39 to obtain the desired contact ofthe gelatin coating with the liquid surface in the trough 36.

Platform 77 and sub-platform 85 are triangular sections, the apex of thetriangular facing the viewer. Depending from subplatform 85 is athreaded shaft 89 passing through support collar 90 which is rigidlysecured to panel 11. Knurled nuts 91 and 92 on opposite sides of thecollar 90, through which the left 89 freely passes, permits the entireassembly of platforms 77 and 85 and trough assembly 35 to be raised orlowered and fixed in the desired position.

The unsensitized film is drawn from supply reel 48 through sprocketassembly 49, 50, 51 over roller 67 along knife edges 38 and underrollers 68 and 94, the excess solution being removed from the gelatincoating by scraper 40.

After the gelatin coating 38a on the tape 39 has been impregnated withthe desired chemicals it passes over positioning roller 66 and entersthe drying chamber 13 through the port 95. Time for drying the coatingis obtained by passing the slowly moving film over positioning rollers96, 97, 98, 99 and drive roller 20. Thence, the film 39 is collected ontake-up reel 21, the temperaturecontrolled air circulated by blower 29having dried the gelatin coating on the film. It will be noted thatafter the tape 39 leaves the scraper 40 the gelatin side of the tape 39does not touch any component of the apparatus or another portion of thetape 39 until it is fully dried and being accumulated on the take-upreel 21.

A cross-section of the drive sprocket 20, idler 23 and lever arm 24 isshown in Figure 4. The idler 23 is pinned to a pair of levers 24 by apin 100, the other end our co-pending application Serial No. 375,032,filed August 18, 1953 and entitled Hydrogen Sulfide Analyzer Recorder,"now issued as U. S. Patent 2,800,397 and of which this application is acontinuation'in-part.

The tape is passed along the trough 36 at a rate of about feet per hourand immediately introduced into the drying chamber 13 wherein atemperature of about 113 F. is maintained, the dried film beingaccumulated on reel 21.

In preparing such sensitized tape the blank film 39 is fed from supplyreel 48 and the gelatin coating thereof contacted at a temperature ofabout 113 F. in trough 36 witha solution of lead acetate and sodiumacetate.

.The tape 39 comprises a uniformly transparent strip having a sensitizedplastic absorptive coating such as of gelatin or agar agar. The strip isof non-reactive, nonporous, non-absorptive flexible material such ascellulose acetate.

The solution for sensitizing the plastic coating is 1 normal leadacetate and 1 normal sodium acetate at a pH of about 6.7. The pH isimportant because if too much acidity is present, sensitivity tohydrogen sulfide is decreased whereas if the acidity is too low, thelead will precipitate from the sensitizing solution with the result thatsubstances such as mercaptans will have greater effect on the stainingof the tape. The sensitized coating obtained from the defined solutionstains uniformly, has the desired optical density for a givenconcentration of hydrogen sulfide, and has low susceptibility tovariations in optical density.

The coating is not light-sensitive and retains its transmittancy whenexposed to the light beam and photoelectric cell arrangement used tomonitor the moving tape as described in our co-pending application.

The apparatus described may be used on 16-min. or 35-mm. film when thesize of the coating trough 36, the block 37, the pad rollers, the supplyand take-up reels, and the tension and drive sprockets are appropriatelyprovided.

Although we have described our invention by reference to a preferredembodiment thereof illustrated in the drawings, it should be understoodthat this is by way of example only. Further, it is contemplated thatmodifications in the apparatus and mode of using the apparatus can bemade without departing from the scope and spirit of the describedinvention.

What we claim is:

1. An apparatus for treating one surface of a moving strip with a liquidtreating agent which comprises in combination an elongated liquid supplytrough having first and second ends, means for maintaining alongitudinally moving strip along said trough adjacent the surface ofliquid therein, means for adjusting the level of liquid in said trough,pen means comprising the upper edges of said trough adapted to applytreating liquid to the underside of such strip, said pen meanscomprising a pair of spaced knife edges extending between said first andseconds ends on opposite sides of said trough, scraper means at thesecond end of said trough adapted to remove excess liquid treating agentfrom the strip as it leaves the trough and to retain the excess treatingagent in the trough, and means for adjustably disposing said troughmeans in alignment with and immediately subjacent the lower side of saidstrip.

2. In an apparatus for liquid treating one surface of a gelatin-coatedacetate strip which comprises in combination elongated liquid-applyingtrough means, constant temperature means for said trough means, movableliquid reservoir means, flexible conduit means between said reservoirand said trough means, an adjustable support for said movable reservoir,adjustable platform means for positioning said trough means with respectto a strip to be treated, pen means applying liquid from said troughmeans onto the lower surface of such strip, said pen means comprising apair of spaced knife edges extending between said first and second endson opposite sides of said trough, and scraper means across the outletend of said trough means adapted to remove excess treating for passing astrip along said trough means over said knife edge pen means and saidscraper means, said scraper means being adapted to retain in saidapplicator trough any excess liquid, constant temperature meanssubstantially surrounding the wall portions of said trough means, andadjustable platform means for said constant temperature means adapted todispose said trough means in alignment with and adjacent to the undersurface of said strip.

4. An apparatus for sensitizing a gelatin-coated acetate tape whichcomprises in combination a panel means, supply reel means on said panel,elongated treating trough means adjustably mounted on said panel, saidtrough means including parallel knife edge means arranged on oppositesides of said elongated trough means as a traceforming pen and a secondknife edge arranged transverse to said parallel knife means to removeexcess treating liquid and retain it within said trough, drying chambermeans mounted on said panel, an entry port into said chamber throughwhich the treated tape may pass, a plurality of pad rollers in spacedarray within said drying chamber means and over which said tape isthreaded in a polygonal path, a take-up reel disposed within said arrayand adapted to receive the treated and dried tape, and drive means fordriving said take-up reel.

5. An apparatus for sensitizing a gelatin-coated surface of afluid-impervious tape which comprises an elongated fluid applicatortrough, opposite sides of said elongated trough comprising parallelknife edges, scraper means fixed across said trough and transverse tosaid knife edges, tape hold-down roller means at opposite ends of saidelongated fluid applicator trough, said rollers being adapted to guidethe tape along the trough in contact with the surface of the fluidtherein, and adjustable fluid reservoir means maintaining the fluidlevel in the said trough, said scraper means being adapted to removeexcess liquid from the tape and to retain such excess liquid within theapplicator trough.

References Cited in the file of this patent UNITED STATES PATENTS1,377,677 Gelbert May 10, 1921 1,391,281 Snyder Sept. 20, 1921 1,837,555Kratz Dec. 22, 1931 2,192,453 Rentsch Mar. 5, 1940 2,368,176 Trist Jan.30, 1945 2,569,755 Grifiith Oct. 2, 1951 2,659,343 Kucher Nov. 17, 19532,790,736 McLaughlin Apr. 30, 1957

